MSA MIDI-In Malfunction

[Highly Solid]

I have built a midi switcher for my amp with the MSA-R and it worked fine when I first used it yesterday. It has since stopped working. I've opened the box and both LEDs light up when I apply power to the circuit. The status LED does not flash when I'm sending MIDI commands or Sysex data and it did when I first used the unit. I have checked that the data is going through by monitoring the MIDI Thru status. Any ideas what the problem may be?

Is it likely that an IC may have burned out because of a voltage spike (I'm using a 12V DC supply). If so, how do I get a replacement?

[John]

I have built a midi switcher for my amp with the MSA-R and it worked fine when I first used it yesterday. It has since stopped working. I've opened the box and both LEDs light up when I apply power to the circuit.

Ok...if LED2 flashes briefly when you power up the MSA, then the microcontroller (IC1) is probably working ok.


The status LED does not flash when I'm sending MIDI commands or Sysex data and it did when I first used the unit. I have checked that the data is going through by monitoring the MIDI Thru status. Any ideas what the problem may be?


Please report your DIP switch settings.
Have you already configured the MSA using SysEx? Please post the contents of the last successful SysEx configuration message sent to the MSA.
What device are you using to send MIDI to the MSA?
What MIDI commands, on what channel are you sending to the MSA?


Is it likely that an IC may have burned out because of a voltage spike (I'm using a 12V DC supply). If so, how do I get a replacement?

A 12VDC supply will not cause any problems. Let's make sure of all the MIDI stuff first--problems are almost always the result of some sort of MIDI configuration issue.

[Highly Solid]

Problem is resolved now. I tried using another computer to send the messages and it started working again. It looks like the driver for my MIDI interface on the computer had become corrupted. I didn't think to look at it initially because the return message from the MIDI Thru port on the MSA was being decoded correctly on the computer. Peculiar.

The 12V supply is showing approx 14V on the MSA board, is this still OK? It seems to be working fine but I don't want to overload anything. I'm using 12V because I have a second device wired in parallel which requires the extra juice.

[John]

The 12V supply is showing approx 14V on the MSA board, is this still OK? It seems to be working fine but I don't want to overload anything. I'm using 12V because I have a second device wired in parallel which requires the extra juice.

That's fine.